(1B) The product $(a+b)(c+d)$
Practice
Expand and simplify.
*Write your answers with powers of $x$ in descending order. $\left(\square x^2 \pm \square x \pm \square\right)$
$\left(x-6\right)\left(x+9\right)$
$\left(x-6\right)\left(x+1\right)$
$\left(x-9\right)\left(8-x\right)$
$\left(-x+7\right)\left(-6+x\right)$
$\left(-7+x\right)\left(x+6\right)$
$\left(3+x\right)\left(-x+9\right)$
$\left(-2+x\right)\left(-3+x\right)$
$\left(6+x\right)\left(1-x\right)$
$\left(x-1\right)\left(5x-7\right)$
$\left(7x-5\right)\left(2x-5\right)$
$\left(-5x+9\right)\left(1-5x\right)$
$\left(x+9\right)\left(7+3x\right)$
$\left(-5+x\right)\left(2x-9\right)$
$\left(7-3x\right)\left(2x-7\right)$
$\left(3-x\right)\left(3-8x\right)$
$\left(9+7x\right)\left(1+2x\right)$